Icon for a display screen



FIG. 1 is a front view of an icon for a display screen showing our new design; and,

FIG. 2 is an additional front view thereof, showing additional unclaimed subject matter.

The broken line showing of the rectangular and square boxes in FIG. 2 and the display screen forms no part of the claimed design. 

The ornamental design for an icon for a display screen, as shown and described. 